Process and apparatus for marking rubber cords and cables



June 30, 1931. G. J. cRowDEs PROCESS AND APPARATUS FOR MARKING RUBBER CORDS AND CABLES Filed May 8. 1929 Fig 3.

a R ow mm w( mf J W e 6 ATTORNEYS Patented June 30, 1931 UNITED STATES PATENT OFFICE GEORGE JACKSON CROWDES, OF DORCHESTER, MASSACHUSETTS, ASSIGNOR TO SIM- PLEX WIRE AND CABLE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS PROCESS AN'D APPARATUS FOR MARKING RUBBER CORDS AND CABLES Application filed May 8, 1929.

This invention relates to improvements in the marking of vulcanized rubber covered cords and cables, vulcanized rubber hose', and similar goods.

The marking of such goods in a permanent .manner is frequently desirable for any of a variety of reasons, identification of the maker or owner or precise identification of the goods for example. The common method of making such goods involves j acketing of the unvulcanized rubber element in a lead jacket, vulcanization of the j acketed rubber element within the lead jacket and stripping of the lead jacket from the vulcanized rubber elel ment.- The application of the lead jacket to the unvulcanized rubber element is commonly carried out by passing the rubber element successively through a maleand a female die and jacketing the rubber element with lead extruded betwen the two dies by means of high pressure. A number of schemes for marking goods so made involving the application of marking devices to the rubber element passing through the male die have hitherto been used but these schemes, as

hitherto used, have involved objectionable disturbance or deformation of the rubber element and many of them have materially increased the expense of the operation.

One commonly used scheme involves the impressing of metal marking tags into the rubber element passing through the male die so that these tags are encased within the lead jacket as part of the rubber element. Another commonly used scheme involves the impressing of an asbestos tape carrying metal marking tags at regular intervals into the rubber element passing through the male die so that the tape and tags are encased within the lead jacket as part of the rubber element. As will be apparent, both of these schemes involve serious displacementof the rubber element at the point of application of the marking device; this displacement is particularly serious in the case of cords or cables with but a thin rubber covering or in the case of rubber hose with thin Walls for example. Such disadvantages limit the usefulness of such marking schemes, making them Wholly useless in some cases.

Serial No. 361,318.

hold this ribbon in position against the rub-l ber element as the latter passes from the male die through the female die inthe jacket forming mechanism and a corresponding external projection on the male die adapted to form a groove in the lead acket corresponding in cross-section to that of the marking ribbon. The marking ribbon advantageously is of the same material, lead, as the jacket to eliminate any special handling of the composite jacket following vulcanization.

A number of advantages are thus secured. Disturbance or deformation of the rubber element is avoided or reduced to a minimum. Rubber elements of practically any rubberthickness may be so marked. The rubber element may be marked regularly at any desired interval. The scheme is of general application to different types of rubber elements. The marking operation is simple and economical.

The invention includes the marking meth- 0d and apparatus for carrying out the marking method.

The linvention will be further described in connection with the accompanying drawings which illustrate apparatus embodying the invention and adapted for carryingr out the invention. It will be understood that the general type of jacket forming mechanism illustrated is well known and, for this reason and in the interest of clarity, only those details pertaining particularly to the invention are particularly described and illustrated, the drawings being diagrammatic in other respects. In the accompanying drawings:

Fig. 1 is a sectional elevation of the jacket forming mechanism showing particularly the relation of the jacket forming dies.

Fig. 2 is an end view ofthe male die of the jacket forming mechanism,

j an indentedinstead of an elevated mark,

Fig. 7 is a fragment ,of a rubber element showing marks applied by the invention to indicate the length of the rubber element, and

Fig. 8 is a cross-section through the male die of thejacket forming mechanism with a rubber elementfand marking ribbon in position therein.

Referring to the drawings, the base 10 supports an element 11 including a'die chamber 13 and a superimposed element l2 including a supply chamber 14 for the jacketing lead. .The male die 15 projects into the die chainber 13 in alignment with the female die 16 vbut spaced therefrom. The male die is provided with an interior passage adapted to receive the rubber element 17, this passage bcing of "smaller diameter than the passage through the female die. The annulus dcfined by the difference in diameter of the passages through the two vdies defines the lead jacket 10 formed on the rubber element in passing through themechanism, solid lead being extruded 'between' the female die and the male die around the rubber element as the latter passes through the female die from the male die by means of forcing means 18, usually a hydraulic ram. So far, this paragraph describes aconventional jacket forming mechanism.

40 Referring particularly to this invention, a

marking ribbon 20 carrying marking means 24, supplied from spool 21, is pass i through l the groove 22 inthe male die 15 with the rubber elementpassing through the interior passage .through the male die. With respect to the rubber element, the marking ribbon forms apart of the wall of the interior passage through the male die, the groove 22 being adapted to receive the marking ribbon and to j so position the marking ribbon with respect to the rubber element. As the marking ribbon and the rubber element pass from the male die through the die chamber- 13 and thence through the female die 16, the marking ribbon forms a part of the Wall of the interior of the lead jacket formed on the rubber element, a corresponding groovevbeing formed in the lead jacket by means of the projection 23. The marking ribbon is held in position against. the rubber element,

berelement, the marks formed by the markmg means 23 are made a permanent part ofthe rubber element, and the marking ribbon and the lead jacket are then stripped from the vulcanized rubber element. marking means 24 may be formed on or in the marking ribbon before it is .supplied to the operation or they may be formed on or in the marking ribbon by passing a blank ribbon from spool 21 over a marking wheel on its x way to the jacket forming mechanism, for

example. The marking ribbon may be shaped to conform to the exterior of the rubber ele- Irent by means of wheels 25. The groove 22 and the projection 23 should conform tothe shape of the marking ribbon as applied to the rubber element.

As noted, the marking ribbon is advantageously of lead, Other materials adapted to retain marking means thereon are also useful in carrying out the invention. Suitable paper or fabric tapes, for example, may be u^ed as marking ribbons.V The marking means may consist of depressions or elevations on the marking ribbon or of perforations in the marking ribbon.

Lead or lead alloys are the most commonly used'jacketingmaterials and lead jacketing materials are therefore referred to more par ticularly herein.l Other plastic metals equivalent in the operation of the jacket forming mechanism are the equivalent of lead with respect to this invention.

Particular reference has also been made herein to rubber elements, rubber covered vcords and cables and rubber hose and similar goods, because the invention is of special application in the marking of such goods. The invention is, however, generally useful in connecti on with the marking of similar goodsfof other materials convertible by means of vulcanization from a plastic to an elastic sta-te.

I claim:

1. In the marking of rubber covered cords, cables, rubber hose and similar goods, the -improvement which comprises forming a lead jacket on the rubber element with a groove The in the inner side thereof and a marking ribbon therein, vulcaniz'ing the acketed rubber element and strippin the jacket from the vulcanized marked ru ber element.

2. In the marking of rubber covered cords, cables, rubber'hose and similar goods, the improvement which comprises forming a lead jacket on the rubber element with a groove in the inner side thereof and a marking ribbon of substantially the size of the groove therein, vulcanizing the jacketed rubber element and stripping the jacket from the vul-v canized marked rubber element.

3. In the marking of rubber covered cords, cables, rubber hose and similar goods, the imrovement which comprises forming a lead jacket on the rubber element with ay marking ribbon embedded in the inner side of the lead -jacket, vulcanizing the jacketed rubber element and strip in the jacket from Ithe vulcanized markedp ru ber element.

4./ In the marking of rubber covered cords, cables, rubber hose and similar goods, the imrovement which comgises extruding a lead Jacket around-the rub r element, formin a groove in the inner side of the lead jac et assaid jacket is extruded aroundv the rubber element, placing a marking ribbon of substantially the size o? the said groove in said yoove during the extrusion of the jacket ,vu canizing the j acketed rubber element an vstrip ing the jacket from the vulcanized marked ru ber element. n 5. In combination with apparatus for jacketing and marking rubber covered cords and cables, rubber hose and similar' goods for vulcanization comprising male and female dies, means for extruding metal between the dies and means for passing the rubber element successivel)7 through the interior passage of the male die and the female die, means for su ,plying a continuous marking ribbon to t e interior assage through the male die with the a5 rubber e ement, and a groove in the interior passage throu h the male die adapted to receive said mar 0ng ribbon. 6. In combination with' apparatus for jacketingand marking rubber covered cords and cables, rubber hose and similar oods for vulcanization comprising male an female dies, means for eXt-ruding metal between the ldies and means for passing the rubber element suc-` n cessively through the interior passage of the male die and the female die, means for supplying a continuous marking ribbon to the interior passage through the male die with the rubber element, and a groove in the interior passage throu h the male die adapted to re- '40 ceive said mar 'n ribbon and a correspondy ing projection on t e male die. n testimony whereof I ailix my signature.

GEORGE JACKSON CROWDES. 

